This application claims the benefit of Japanese Application Nos. 2001-221909 filed on Jul. 23, 2001, 2001-221910 filed on Jul. 23, 2001, 2001-239755 filed on Aug. 7, 2001, 2001-245606 filed on Aug. 13, 2001, 2002-6479 filed on Jan. 15, 2002, 2002-12097 filed on Jan. 21, 2002, 2002-126727 filed on Apr. 26, 2002, and 2002-151375 filed on May 24, 2002 respectively, the contents of which are incorporated by reference.
Field of the Invention and Description of the Related Art
The present invention relates to an endoscope having a treatment instrument passage channel and capable of performing various kinds of treatments by swinging a treatment instrument that is projected through an opening of the treatment instrument passage channel.
Endoscopes for medical use have been widely adopted in the past. An elongated insertion unit of such an endoscope is inserted into a body cavity in order to observe an organ within the body cavity or in order to, if necessary, perform various cures or treatments using a treatment instrument passed through a treatment instrument channel.
In recent years, such a procedure has been widely appreciated that resects a lesion in a body cavity using an endoscope that includes a plurality of treatment instrument passage channels and that has different treatment instruments passed through the treatment instrument passage channels.
For example, Japanese Unexamined Patent Application Publication No. 2000-37348 describes an endoscope for therapeutic use that is designed to include two treatment instrument passage channels and to have various treatment instruments passed through the treatment instrument passage channels.
In the above endoscope for therapeutic use, a forceps raising device is included in a distal opening portion of one treatment instrument passage channel. The forceps raising device moves away from the distal opening portion of the other treatment instrument passage channel. A clamping treatment instrument (hereinafter referred to as clamp forceps) and an incising treatment instrument (hereinafter referred to as a cutting instrument) such as a cautery knife needle are used in combination for treatment. Herein, the clamping treatment instrument is passed through the treatment instrument passage channel including the forceps raising device, while the incising treatment instrument is passed through the other treatment instrument passage channel.
To be more specific, after the mucosa of a lesion or a nearby region is clamped using the clamp forceps, the clamp forceps are moved away from the treatment instrument passage channel through which the cutting instrument is passed. The pulled mucosa is then resected using the cutting instrument.
However, as far as the endoscope for therapeutic use described in the above publication is concerned, a guiding means for resecting the mucosa, which is pulled using the clamp forceps, sideways with the cutting edge of the cutting instrument has not been described at all. With the features of the endoscope for therapeutic use, the cutting edge of the cutting instrument must be guided by angling the endoscope. This poses a problem in that the clamp forceps and a field of view offered by the endoscope move along with the angling.
Moreover, it is hard to delicately manipulate the cutting edge of the cutting instrument by angling the endoscope. Incising work becomes very hard to do. Besides, A range resectable with one manipulation is limited.
An object of the present invention is to provide an endoscope that proves excellent in performing endoscopic treatment with a treatment instrument projected through a distal opening of a treatment instrument passage channel.
Another object of the present invention is to provide an endoscope permitting an operator to easily maintain a state in which an object region to be treated and the distal part of a treatment instrument are caught in a field of view, and to easily perform treatment using the treatment instrument.
According to the present invention, an endoscope has an objective optical system that picks up an endoscopic image, and a treatment instrument passage channel, which introduces a treatment instrument to a body cavity, disposed in a distal part of an insertion unit thereof.
A treatment instrument swing stand permitting the distal part of a treatment instrument to move in both the rightward and leftward directions of the endoscope with a centerline, which bisects a field of view in the rightward and leftward directions, as a border is disposed near a distal opening portion of the treatment instrument passage channel. Thus, the distal part of the treatment instrument can be moved in the rightward and leftward directions of the endoscope over a wide range while being caught in the field of view.